The present invention relates to a golf club head, more particularly to an improved structure of the face portion being capable of improving the coefficient of restitution.
In order to increase the carry of the struck ball, various improvements have been made on the face portion of a golf club head for the purpose of increasing the coefficient of restitution of the face portion.
In case of a golf club head having a hollow behind the face portion, for example, the face portion is made using a thin metal material to improve the flexure when hitting a ball. In this case, even if a material having flexure strength is used, it is difficult to provide sufficient durability for the impact area or the central portion of the clubface. In another design, therefore, to achieve a high restitution coefficient and durability at the same time, a groove is formed on the periphery of the back face of the face portion to leave the impact area thicker. In this case too, the improvement has its limit as is usual, and even if the width and depth of the groove are well controlled, it is difficult to further the improvement in the coefficient of restitution.